Crimping apparatus for manufacturing a bulky yarn

ABSTRACT

An air-jet type crimping apparatus equipped with a fiber ejection nozzle of an increased thermal effect, a rotational crimping member having a surface on which are peripherally arranged needle or honey-combed protuberances defining a multiplicity of spaces receptive of the fibers ejected by the nozzle composing the yarn and cone-type means for taking up the yarn from the surface at speeds automatically adjusted according to variations in the thermal shrinkability of the processed fibers. Fiber cooling means may advantageously be added for enhanced stability of the crimps imparted to the fibers.

United States Patent Ozaw et al. [451 Apr. 18, 1972 [54] CRIMPINGAPPARATUS FOR 3,143,784 8/1964 Scott ..28/1.4 x MANUFACTURI A BULKY A3,217,386 11/1965 Clendening.... ..28/ 1.4 X 3,251,181 5/1966 Breen etal..... .....28/72.l2 X [72] inventors: Goro 0zaw; Kenz Kosaka; Kiyoshl3,255,508 6/1966 Weiss et al ..28/1.4

Adachi; Tsutomu Okaya; Takeo Ariki, all of Nagoya-shi, Japan PrimaryExaminer-Louis K. Rimrodt [73] Assign: Mitsubishi Rayon Company Limited,AttorneyRobert E. Burns and Emmanuel]. Lobato Japan 57 ABSTRACT [22]med: 1970 An airjet type crimping apparatus equipped with a fiber ejec-[2]] Appl. No.: 4,827 tion nozzle of an increased thermal effect, arotational crimping member having a surface on which are peripherallyarranged needle or honey-combed protuberances defining a [30] FomgnApphcauon Pnomy Data multiplicity of spaces receptive of the fibersejected by the Aug. 26, 1969 Japan ..44/67084 n zzl mp ing he y n ancone-type means for taking up the yarn from the surface at speedsautomatically adjusted ac- [52] us. C1 ..28/1.4 r i g o v ri ion in thethermal shrinkability of the [51] Int. Cl ,|)02 1/16 processed fibers.Fiber cooling means may advantageously be [58] Field of Search ..28/1.4,72.12, 75 added for enhanced stability of the crrimps imparted to thefibers. [56] References Cited UNITED STATES PATENTS 8 Claims, 6 DrawingFigures 2,067,251 l/ 193 7 Taylor .2 8/ 72 ,12 X

PATENTEDAFR 18 I972 SHEET 1 OF 3 ATTORNEY PATENTEDAPR 18 N37? SHEET 2[IF 3 The present invention relates to an improved crimping apparatusfor manufacturing a bulky yarn, and more particularly relates to animproved apparatus for imparting crimps to thermoplastic filamentaryfibers by ejecting, together with a heating medium, the heatedfilamentary fibers onto a rotationaltype crimping member.

Conventionally, manufacturing of bulky yarns is generally performedutilizing a false-twisting system, a stuffing-box system or anainjet-ejection system. However, most of the conventional systems haveshortcomings in the actual use thereof in manufacturing processesbecause of their mechanical design complexity, operational techniquedifficulties, because they dont provide sufficient freedom in theselection of the crimp shape to be imparted to the processed filamentaryfibers.

In order to improve the above-described disadvantages, a novel crimpingapparatus of a jet-ejection type has already been proposed regarding themanufacturing of desirable quality bulky yarns. In the case of thisproposed technique, a yarn composed of thermoplastic filamentary fibersis ejected against a crimping member together with a heating medium flowfor mutual fiber entanglement and heat setting. The

. crimping member is designed in the form of a rotational cylinderperipherally provided with a brush, needle or porcupine-type surface.

Since the original invention of the above-described type crimpingapparatus, several improvements have been added thereto and even largefineness yarn crimp impartation for use in carpets became possible dueto accumulation of such improvements. This was quite difficult in thecase of another crimping technique. Especially, in case the processedyarn was composed of polypropylene fibers, it was difficult to providethe yarn with crimps of a desirable and stable nature, because thepolypropylene fiber has a relatively large polymer crystallinity and theterminal groups thereof are not provided with a chemically or thermallyreactive nature. Although employment of the above-described improvementsenabled desirable crimp impartation even to such polypropylene fibers ofthe jet-ejection type crimping system, still no satisfactory operationalfunction can be assured by the mechanical features of the conventionaljet-ejection type crimping apparatus.

ln the case of the conventional crimping apparatus, a continuous yarn isintroduced into an ejection nozzle together with a suitable heatingmedium such as heated air or steam, heated through contact with theheated medium while passing through the ejection nozzle and ejectedagainst a barrier, which is located facing an outlet of the ejectionnozzle in a spaced relationship, for crimp impartation. Generally, the e'ection nozzle is composed of a yarn guide tube and a yarn e ection tubeconsolidated with the yarn guide tube in a mutually superposedrelationship. A yarn ejection tube outlet is located downstream of ayarn guide tube outlet in an adequately spaced relationship and theprocessed yarn is heated within the space between the two outlets by theheating medium introduced therein. 80, provided that the heating mediumtemperature and type are once settled, the heating medium thermal effecton the processed fibers is apparently dependent upon the distancebetween the two outlets.

In case the referred distance is short, the effective fiber heating timebecomes considerably short when the yarn is processed at a high speed,that is, the thermal effect on the processed fibers is lowered.Therefore, it becomes necessary to desirably and effectively impartcrimps to such yarns of less heat reactive fibers such as apolypropylene yarn of relatively large fineness.

When the distance is elongated, there may be a lowering in the suckingeffect on the processed yarn by ejection of the heated medium. So, inthe initial introduction of the yarn through the ejection nozzle, itbecomes necessary to cease the heated medium supply into the space for asmooth yarn passing or to use an adequate yarn guide hook or the like.

Further, the processed yarn tends to vibrate while advancing through thelengthened space and such yarn vibration forms a bar in the high speedcrimping operation.

Still another disadvantage of the conventional crimping apparatus existsin the unstable removal of the fibers from the rotational cylinder typecrimping member. After being ejected onto the crimping membersperipheral surface, the processed fibers are allowed to stay within thespaces formed on the surface due to the presence of needles or likemembers. The length of this stay time varies as the shrinkability of theprocessed fibers varies, that is, the location of fiber removal from thesurface also tends to vary. Perhaps this variation in the fibers removalpoint can be compensated for by adjusting the crimped fibers take-upspeed, accordingly. However, this kind of speed adjustment is quitedifficult to carry out in the actual production process.

When the actual fibers removal point deviates from the optimumlydesigned removal point, resistance against smooth fiber removal from thecrimping members surface increases. This resistance increase leads toundesirable formation of fluffs or loops on the resultant yarn, breakageof the needles or like members due to excessive yarn tension or yarnbreakages caused by irregular fiber removal. Such drawbacks will befurther increased in the case of a high speed crimping operation.Therefore, an effective variation control in the abovedescribed fiberremoval point is a key factor in achieving the high speed crimpingoperation, that is, enhancement of the systems productivity.

A principal object of the present invention is to provide an improvedcrimping apparatus capable of assuring a considerable productionincrease.-r""

Another object of the present invention is to provide an improvedcrimping apparatus capable of eliminating operational drawbacksencountered in the prior arts.

Still another object of the present invention is to provide an improvedcrimping apparatus producible of bulky yarns having crimps of desirableproperties.

A further object of the present invention is to provide an improvedcrimping apparatus capable of imparting stable crimps to the processedfibers.

A further object of the present invention is to provide an improvedcrimping apparatus of simple mechanical design.

In order to attain the above-described objects, the apparatus of thepresent invention is provided with a pair of feed rollers, an ejectionnozzle located downstream of the feed rollers, a rotational crimpingmember disposed relative to the ejection nozzle and provided withnumerous superficial spaces formed by needles or protuberances and aparticularly designed yarn take-up means for removing the yarn from thecrimping members surface. The ejection nozzle is provided with asupplementary heating medium path encircling a main heating tube forsufficient heating of the processed fibers. The rotational crimpingmembers peripheral surface is receptive of the fibers ejected from theejection nozzle outlet. The yarn take-up means is generally in the formof a pair of cooperating substantially conical rollers. A contact lineof the rollers is directed perpendicularly to the crimping member'srotational axis and the rollers large-diametral ends are directed towardthe crimping members rotational direction. The yarn take-up speed can beautomatically adjusted in response to the variation in the processedfibers shrinkability.

For better stability of the crimps imparted to the fibers, the apparatusof the present invention may advantageously be provided withfiber-cooling means and is located in the vicinity of the fibers removalpoint from the rotational crimping member.

Using the apparatus of the present invention, a considerably high speedcrimping operation can be assured. For example, even a polypropyleneyarn of 1850 denier thickness can be processed at a speedup to 250 m/minand a nylon yarn of 1,260 denier thickness, which has an excellentconformity to heat setting, can be processed at a speed up to 350 m/min.In case of a polyester yarn, it can be processed at a speed slower thanthe case of nylon yarn but faster than polypropylene.

Other features and advantages of the present invention will be morefully introduced in the following descriptions, reference being made tothe accompanying drawings, in which;

FIG. 1 is an explanatory side view of an embodiment of a crimpingapparatus according to the present invention,

FIG. 2 is a lengthwise cross-sectional view of an embodiment of theejection nozzle used in the crimping apparatus of the present invention,

FIG. 3 is a side view partly in section a of the ejection nozzle shownin FIG. 2 for illustrating a switching operation.

FIG. 4 is a cross-sectional view of conduits for supplying the heatingmedium to individual ejection nozzles,

FIG. 5 is an explanatory side view of yarn take-up means used in theapparatus of the present invention,

FIG. 6 is a perspective view of an embodiment of the crimping apparatusof the present invention equipped with fibercooling means.

In a fundamental embodiment of the apparatus of the present inventionshown in FIG. 1, a pair of feed rollers 2a and 2b are located downstreamof a given supply source (not shown) of a multifilament yarn 1. Locateddownstream of the feed rollers 20 and 2b, is a cylindrical-typerotational crimping member 5 which rotates in a direction shown by anarrow in the drawing. A peripheral surface of the crimping member 5 isis provided with numerous spaces 5b formed by numerous needle-likeprotuberances 5a planted thereon. At a position downstream of the feedrollers 2a and 2b, a fiber ejection nozzle 3 is disposed with itsejection outlet closely directing the peripheral surface of the crimpingmember 5. The ejection nozzle 3 is supplied with a compressed heatingmedium flow 4 from a given supply source (not shown). Located in thevicinity of the fibers planed removal point, is a pair of cooperativesubstantially conical delivery rollers 6a and 6b, whose mechanicaldesign will be hereinafter explained in detail.

In the above-described mechanical design of the apparatus of the presentinvention, the multifilament yarn 1, from the given supply source, isfed into the ejection nozzle 3 at a constant speed by the pair of feedrollers 2a and 2b. Passing through the ejection nozzle 3, themultifilament yarn 1 is accompanied with the heating medium 4, underpressure, for example steam, also introduced thereinto and ejectedthrough the ejection outlet of the ejection nozzle 3 and together withthe heating medium, onto the peripheral surface of the crimping member5. Due to the ejection under pressure, fibers in the multifilament yarnl are pushed into the spaces 5b on the surface and crimped therein andcarried toward the removal point as the crimping member 5 rotates.Arriving at the removal point, the fibers in the multifilament yarn 1are removed or take off from the surface by the conical delivery rollers60 and 6b and taken-up by a suitable winder (not shown).

As is already briefly mentioned, the apparatus of the present inventionis firstly characterized in the mechanical design of the fiber ejectionnozzle 3. The fundamental requirements for the functional feature of thefiber ejection nozzle 3 are (a) suf' ficient thermal effect on theprocessed fibers even at a high speed, (b) less damage to the fibers and(c) fewer troubles in the operation and handling thereof.

Reiterating the former description, none of the conventional ejectionnozzles can fulfill the above-described requirement without discrepancy.

Referring to FIG. 2, a typical embodiment of the fiber ejection nozzlefavourably used in the apparatus of the present invention is shown. Theejection nozzle 3 comprises a yarn guide tube8 having a centrallongitudinal bore receptive of the yarn l to be processed and anejection tube 7 adjustably threaded into the yarn guide tube 8 at itsupstream end. As is shown in the drawing, the yarn guide path 8a of theyarn guide tube 8 elongates into a central longitudinal bore of theejection tube 7. Through the central longitudinal bore of the ejectiontube 7, a centrally bored main heating tube 9 extends in an annularlyspaced relationship to the ejection tube 7. This annular space forms asupplementary space 11 for a heating medium path. A downstream end ofthe main heating tube 9 is connected to the downstream end of theejection tube 7 and forms an ejection outlet of the fiber ejectionnozzle 3. An upstream end of the main heating tube 9 meets the elongatedyarn guide path 8a of the yarn guide tube 8 in an annularly spacedrelationship. The central bore of the main heating tube 9 is connectedwith the supplementary heating medium in the annular space 11 by aconnecting space 12 and a connecting path 13. The supplementary heatingmedium space 11 is connected to a given source (not shown) of theheating medium 4 by a supply conduit 10. The positional relationshipbetween the ejection tube 7 and the yarn guide tube 8 can be changed asdesired by adjusting the thread 14 connection.

The multifilament yarn 1 to be processed, is introduced into the yarnguide tube 8 as shown by an arrow. At this introduction, the yarn l iseffected by a suction force presented by a heating medium 4, underpressure introduced into the fiber ejection nozzle 3 through the supplyconduit 10. Coming into the central bore of the main heating tube 9, theyarn l is accompanied with the compressed heating medium 4 alsointroduced thereinto through the paths l2 and 13 and is heated. Togetherwith this direct heating effect, the processed yarn l is additionallyand indirectly heated by the heating medium 4 introduced into thesupplementary heating medium space 11. Thus, the effective length of theheating zone can be elongated and the presence of the centrally boredmain heating tube 9 assures effective prevention of the fibersdisturbance during processing through the ejection tube 3. Although themajor fibers disturbing effect is prevented, the direct contact of thecompressed heating medium 4 with the processed yarn -1 within the mainheating tube 9 brings about a moderate and desirable entangling actionon the fibers composing the yarn 1 and, due to this fiber entanglingeffect, the fibers in the yarn are brought into an increased bundledcondition.

Being ejected through the ejection outlet of the ejection tube 7, thefibers in the multifilament yarn l are deposited onto the peripheralsurface of the crimping member 5 and are, due to the ejection force,pushed into the numerous spaces 5b formed on the surface for a physicaldeformation in a heated condition, that is, for crimping.

The shape of the crimps acquired on the fibers in the abovedescribedtechnique is quite distinctive in that the individual fibers arefavourably entangled with each other and that the formed crimps arerandomly distributed over the fibers composing the yam. This isfundamentally different from the crimp shapes obtained by theapplication of the conventional crimping techniques such as thefalse-twisting system of conventional stuffing box system. Namely,individual fibers are provided with smooth three-dimensional curves.Because of the above-described distictively shaped crimps, the resultantmultifilament yarn can be provided with an enriched bulkiness and a softhand feeling. When multifilament yarns of this type are used formanufacturing a tufted carpet, the desired product can be obtained byusing a lesser yarn quantity when compared with yarns manufactured byanother method.

The feed rollers 2a and 2b may be constructed in the form of ordinaryrollers or in the form of conical rollers as shown in FIG. 6, the latterassuring effective yarn supply speed control. In this case, the nippoint selection of the yarn l by the pair of conical rollers 20 and 2bcan be carried out as desired by using an adequate yarn guide (notshown) and, when the nip point is selected on the larger diametralportion of the rollers 2a and 2b, the yarn 1 will be supplied to theejection nozzle 3 at a higher supply speed. Thus, the supply speed ofthe yarn l to the ejection nozzle 3 can be changed as desired bydisplacing the yarn guide along the contact line of the pair of feedrollers 2a and 2b, accordingly.

During the manufacturing operation of the crimped yarn, there are somecases when the ejection of the heating medium needs to be stopped. Thisusually happens at the time of initial yarn introduction through theejection nozzle 3. For example, provided that a yarn of polypropylenefibers is processed through the crimping operation, thermal treatment isperformed at a temperature almost equal to a fiber melting point. So, ifthe yarn is initially introduced through the ejection nozzle 3 withoutturning off the heating medium supply of such a high temperature, thefibers in the yarn tend to become molten and the initial introduction ofthe yarn through the ejection nozzle will end in failure. For carryingout the initial introduction of the yarn successfully, it is necessaryto momentarily turn off the heating medium supply to the ejectionnozzle.

Referring to FIG. 3, an embodiment of the mechanism for enabling thisheating medium supply switching is shown. In this mechanism, the supplyconduit of the ejection nozzle 3 is switchably connected to a mainsupply conduit through an aperture 16 of the latter. In a conditionshown with full lines in the drawing, that is, the outlet of theejection tube 7 is positioned adjacent to the peripheral surface of therotational crimping member 5 in its operating condition, the heatingmedium 4 is passable through the connection by the aperture 16 and isintroduced into the ejection nozzle 3. In a condition shown with dottedlines in the drawing, that is, the outlet of the ejection tube 7 ispositioned remotely away from the peripheral surface of the crimpingmember 3 in its standby condition, the connection between the supplyconduit 10 and the main supply conduit 15 is closed and the supply ofthe heating medium 4 into the ejection noule 3 is turned off.

Be employing the above-described mechanical designs switching mechanismin the crimping apparatus of the present invention, the followingpossibilities will be assured.

I. In case two or more ejection nozzles are used together in an aligneddisposition, the respective yarn supply switching can be easilyperformed by only pivoting the corresponding ejection nozzle assemblyaround the main supply conduit in a manner independent from each other.

2. If the pivotal contact between the ejection nozzle assembly and themain supply conduit is adequately sealed with a heat resistant substancesuch as Teflon, a smooth assembly pivotation due to a sealing substancelubricational effect can be assured in addition to an effective pressuresealing.

The ejection nozzle or nozzles 3 can be either laterally stationary withrespect to the rotational axis of the crimping member 5 or movable inthat direction. In this regard, the crimping member 5 may be slidable inits axial direction, also. Consequently, by designing both as mutuallymovable in the above-described sense, the following possibilities canresult.

1. Because the ejection point by the ejection nozzle 3 is laterallydisplaced on the peripheral surface of the crimping member 5, themechanical attack on the surface by the ejection can be distributed overa long distance and local damage of the needle-like members orhoneycombed protuberances planted on the surface can be effectivelyobviated. Consequently, the needle-like members or honey-combedprotuberances are durable for long periods of use.

2. Because the deposited yarn is maintained on the surface in a zig-zagform because of the pins, the effective stay of the yarn on the surfacecan be elongated resulting in high speed impartation of stable crimps onthe fibers.

The above-described lateral movement of the ejection nozzle or nozzlescan be carried out by utilizing a suitable cam driving mechanismpositioned sideways of the crimping member 5. In this case, no troublewill occur in the removal action of the yarn or yarns from the surfaceif the lateral sliding width is in a range from 10 to 15 mm.

Referring to FIG. 4, an embodiment of the arrangement for performing thedistribution of the heating medium to a plurality of aligned ejectionnozzles is shown. In the arrangement, a plurality of ejection nozzles30, 3b, 3c, .3n are connected respectively to the main supply conduit 15in an adequately spaced and aligned disposition. The main supply conduit15 is internally provided with one or more auxiliary heaters extendingtherein through for obtaining a uniform temperature distribution overall ejection nozzles 30, 3b, 3c,

. 3n. The heating medium 4, supplied from a given supply source (notshown) through the main supply conduit 15, is additionally heated by theauxiliary heater or heaters 20 and distributed to each ejection nozzle3.

By adopting the auxiliary heater 211) of an electric type, thetemperature can be easily changed as desired by adjusting the magnitudeof the electric voltage used, only.

In case the above-described heating medium distributing arrangement isused, the following advantages will thereby result.

I. The heating medium can be distributed uniformly to each ejectionnozzle and the possible temperature lowering of the medium during thedistribution can be effectively compensated for by the presence of theauxiliary heater or heaters disposed in the main supply conduit.Uniformity in both temperature and distribution can be assured.

2. Because the ejection nozzles are pivotally disposed to the mainsupply conduit, thermal radiation through the conduits wall can beeffectively minimized and enhanced.

thermal efiiciency can be assured.

3. In this arrangement, the main supply conduit itself forms "1 l asupport of the ejection nozzles, so a simple mechanical arrangement willresult.

The angular relationship of the ejecting direction with I respect to theperipheral surface of the crimping member also plays an important rolein determining the crimping effect on the apparatus of the presentinvention. In this regard, it is favourably recommended that theejecting direction of the ejection nozzle 3 is perpendicular to avirtual tangent plane contacting the circle formed by the peripheralsurface of the crimping member 5 at the ejection point. When the angularrelationship is selected in this manner, the ejection force provided bythe heating medium under pressure can be mostly utilized in pushing theyarn 1 sufficiently into the spaces 5b and, consequently, crimpimpartation can be performed with satisfactory results even in the caseof relatively large thickness yarn.

The distance between the outlet of the ejection noule 3 and theperipheral surface of the crimping member 5 should advantageously beselected as short as possible. By thusly selecting the interveningdistance, the difference between the fibers ejection pressure and thefibers push-in pressure can be almost minimized and a sufficient crimpimpartation will be ascertained. This distance should favourably be 10mm or shorter and when the heated medium is ejected from such a closeposition to the surface of the crimping member, the ejected medium tendsto reflect from the surface and escalate the temperature of theatmosphere surrounding the crimping member 5 for enhanced thermal effecton the fibers composing the yarn 1.

Referring to FIG. 5, a mechanism for adjusting the crimped yarns removalspeed from the crimping member's peripheral surface is shown. In thevicinity of the planed removal point of the crimped yarns 21a, 21b and21c from the surface of the crimping member 5, the pair of cooperatingconical delivery rollers 60 and 6b are positioned. A contact line of therollers 6a and 6b is directed almost perpendicularly to a radial lineextending from the rotational axis of the crimping member 5 and thelarge-diametral ends of the rollers 6a and 6b are directed toward therotational direction member 5.

After the fibers inthe supplied multifilament yarn 1 is provided withcrimps during their stay in the spaces 5b on the crimping memberssurface, they must be removed therefrom.

Provided that the crimped yarn 21 is removed from the surface into adirection parallel to the extending direction of the needle-likeprotuberences 5a at a location A on the surface, the removal speed ofthe crimped yarn 21 is determined in accordance with a nominal fiberthermal :shrinkability composing the yarn 1. When the actual fiberthermal shrinkability is smaller than the nominal value, the actualremoval point of the yarn 21 deviates towards a downstream location B.Due to these positional deviations, the nip point of the yarn 21, by theof the crimping rollers 6a and 6b, moves towards the large-diametralends of the rollers 6a and 6b, the yarn 21 is now taken up at anincreased take-up speed and the actual removal point gradually returnsto its initial location A. On the contrary, in case the actual thermalshrinkability is larger than the nominal value, the actual removal pointof the yarn 21 deviates towards an upstream location C, the nip point ofthe yarn 21, by the rollers 60 and 6b, moves towards the small-diametralends of the rollers 6a and 6b, the yarn 21 is now taken up at adecreased take-up speed and the actual removal point gradually alsoreturns to its initial location A.

In the manner above-described, the crimped yarn 21 can be removed fromthe surface of the crimping member at an optimum removal point whereonthe resistance against removal is smallest in accordance with thelengthwise variation in the thermal shrinkability of a single yarn orvariation in the thermal shrinkabilities of a plurality of yarns.

The percent degree of the surface taper of the rollers 6a and 6b is soselected as to be slightly larger than the percent variation ordeviation of the yarns thermal shrinkability. For example, when thepercent fluctuation of the yarns thermal shrinkability is i 7, thepercent increase in the rollers diameter at its largest-diametral endshould favourably by about 10% with respect to the rollers diameter atits middle length portion and the percent decrease in the rollersdiameter at its smallestdiametral end should favorably be about l0% inthe same sense. One of the pairs of rollers 6a and 6b is constructed inthe form of a driven roller and the other in the form of a pressureroller, the latter being preferably urged towards the former utilizing asuitable urging mechanism such as a spring. By employing the taking upmeans of the above-described type, it is possible to process two or moreyarns simultaneously to the crimping member and to bundle them togetherat the time of yarn take-up without enlarging the occupying space by thetaking-up means. The taking-up means of the present invention isprovided with a relatively simple mechanical design and is accompaniedwith ease in the handling operation. Further, even in case two or moreyarns are to be nipped by the delivery rollers 6a and 6b, the removalpoint automatically displaces sideways, as above-explained, for aneffective prevention of the locational damage to the rollers surface andthe fibers contained in the yarns can be somewhat opened due to arubbing effect by a sliding contact of the yarns with the rollerssurface during the lateral displacement.

As is already explained in the foregoing description, fibers composingthe multifilament yarn l and ejected from the ejection nozzle 3 arepushed into the spaces 5b formed on the crimping members surface by thenumerous protuberances 5a and are deformed into crimped configurationduring their stay in the spaces 5b. A superior crimping effect resultsfrom a superior thermal effect. In this regard, however, sufficientcooling of the crimped fibers can hardly be attained during their periodof stay within the space 5b, that is, during the period from ejection toremoval. lnsufiicient cooling of the crimped yarn often tends to lead toa variable crimping effect and disappearance of the imparted crimps.Although increase in the crimping members diameter may somewhat obviatethis drawback, it tends to result in enlargement of the wholearrangement of the apparatus, trouble in driving the apparatus of suchan enlarged arrangement and less adaptability for an effectivemass-production.

A mechanism for achieving the above-described effective cooling of thecrimped yarn is illustrated in FIG. 6, wherein the mechanism comprisesyarn cooling means 17 disposed facing the crimping member 5 in thevicinity of the yarn removal point. The yarn cooling means 17 comprisesa pair of slidably superposed perforated plates 18a and 18b and thecooling air flow rate passable therethrough can be changed as desired byadjusting the superposed relationship between the two plates 18a and18b. The yarn cooling means 17 can also be in the form of a perforatedplate slidably superposed with a shutter plate and the cooling air flowrate passable therethrough can be changed as desired by adjusting thesurface area of the perforations through sliding of the shutter plate.

By providing the crimping apparatus of the present invention withcooling means of the above-described type, it becomes possible toshorten the time the crimped yarn stays within the spaces 5b on thecrimping members surface while insuring a sufficient cooling effect onthe yarn within a short period. This results in desirable compactness ofthe apparatuss construction, that is, the diameter of the crimpingmember can be minimized without lowering the stability of the impartedcrimps. The intervening distance between the opening of the coolingmeans and the peripheral surface of the crimping member shouldpreferably be 20 mm or shorter.

It is also recommendable to provide the crimping member of the presentinvention with a plain peripheral surface. When the heated multifilamentyarn 1 is transferred on the peripheral surface of this design, the yarnportion contacting the surface portion having needle-like protuberanceswill be provided with crimps and the yarn portion contacting the plainsurface portion will not be provided with crimps. Thus, the resultantyarn can be provided with a novel configuration, wherein the crimpedportions and the non-crimped portions alternatively extend lengthwise.

The crimping member of the present invention can be made not only in theform of a cylinder but also in the form of an endless belt. Further, theprotuberances are not limited only to needle-like members orhoney-combed protuberances. Various types of protuberances can be usedto define spaces in conformity to the requirement of the end products.

As is well understood from the foregoing discussion, the yarn processedthrough the crimping apparatus of the present invention can possessexcellent entanglement of the component fibers and a random dispositionof the component fibers in the yarn configuration. The shape of thecrimps thus obtained is essentially different from those obtained by theconventional technique and the individual filamentary fiber is providedwith three-dimensional smooth curves in its shape.

Therefore, the crimped yarns manufactured on the crimping apparatus ofthe present invention are provided with enriched bulkiness and soft andcomfortable hand feeling. They are further advantageous in that, whenthe yarns are used for textile products such as carpets, a lesserquantity of yarn is necessary than in the case where the crimped yarnsare manufactured on the conventional-type crimping apparatuses.

Further, employment of the ejection nozzle of the type shown in FIG. 2achieves the following advantageous results.

1. Because the heating medium passes through the path encircling themain heating tube, the heating tube can be supplementally heated and theyarn passing through the main heating tube can be indirectly heatedresulting in a remarkably enhanced thermal efficiency.

2. The processed yarn can be subjected to direct contact with theheating medium for a long distance, that is, the main heating tube iselongated and, accordingly, the fibers in the yarn can be sufficientlyheated at a desired temperature.

3. By making the distance between the yarn guide tube and the heatingtube adjustable, the ejection force of the yarn can be adjusted asdesired. Further, when a plurality of ejection nozzles are used in analigned arrangement, the crimp impartibility of the number of ejectionnozzles can be equalized.

Owing to the above-described advantages, the apparatus of the presentinvention can produce crimped yarns of various types.

Further, due to the installation of the take-up speed adjustingmechanism, the yarn can be taken off from the peripheral surface of thecrimping member at a position of the minimum removal resistanceregardless of the variation in the thermal shrinkability of thecomponentary fibers of the yarn. In addition to this, local damage ofthe protuberances can be effectively prevented resulting in considerablelongevity of the apparatus.

Further, such operational troubles as yarn breakages or fluff formationcan be advantageously obviated ascertaining production of bulky yarns ofenhanced quality. Simple mechanical construction of the taking-up meansremarkably contributes to enhancement in the productivity.

It should again be well understood that by using the crimping apparatusof the present invention, yarns of large thickness can be processedthrough the crimping operation at high speed without incidences of yarnbreakage accidents. Relatively simple mechanical construction andoccupying space of the apparatus can present a great advantage in thepractical production of the crimped yarn.

The following examples are illustrative of the art of the same.

EXAMPLE 1 A polypropylene multifilament yarn of 1,850 denier thicknesscontaining 120 filaments was supplied to a crimping apparatus of thepresent invention, a conventional ejection nozzle of a short heatingdistance type and an ejection nozzle of the present invention shown inFIG. 2 being simultaneously used in an aligned arrangement on a samecrimping apparatus. The crimping operation was carried out under thefollowing processing conditions.

Processing speed Heating medium Heating temperature (Temperature of themediumat the outlet of the ejection nozzle) Pressure of the steam withinthe ejection nozzle Supply speed of the yarn Surface speed of therotational crimping member 90 mlmin super-heated steam 1.6 kg/cm Theresultant crimp-property of the yarns was as is shown in the followingTable 1.

TABLE 1 Type of Percent crimp Percent Percent crimp nozzles usedelongation crimp recovery Conventional 33.7 20.5 84.0 Present Invention43.2 26.8 83.2

EXAMPLE 2 Nylon 6 multifilament yarn of 1,260 denier thicknesscontaining 60 filaments was processed through the apparatus, the same asthat used in the foregoing example, and using two types of nozzles. Theprocessing conditions were as follows.

Process speed 140 m/min Heating medium super-heated steam Heatingtemperature 190 C Pressure of the steam 1.8 kg/cm within the nozzleSupply speed of the yarn S urface speed of the rota- I10 tional crimpingmember The resultant yarns were provided with crimp properties as shownin Table 2.

TABLBZ Type of Percent crimp Percent Percent crimp nozzles usedelongation crimp recovery Conventional 49.8 27.5 85.3 Present invention63.3 34.7 84.]

Even in the case of nylon fibers, the superiority of the ap-' EXAMPLE 3In this experimentation, two types of ejection nozzles the same withthose used in Example 1 were used for processing a polyestermultifilament yarn of 1,560 denier thickness containing 60 filaments ata processing speed of MPM. Super heated steam was used as the heatingmedium and the heating temperature was of 205 C. Pressure of the usedsteam within the ejection nozzles was of 1.9 kg/cm and the ratio of thesupply speed of the yarn with respect to the surface speed of therotational crimping member was of 11.5. The resultant crimpproperty ofthe yarns was as is shown in the following Table 3.

TABLE 3 Type of Percent crimp Percent Percent crimp nozzles usedelongation crimp recovery Conventional 45.1 25.3 84.5 Present invention58.4 30.5 85.0

As is apparent from the above-shown results, an appreciable effect canbe expected for use of the ejection nozzle of the present invention asto polyester fibers. By enhancing the heat-settability of the polyesterfibers to be processed, it is feasible to employ a higher processingspeed of the yarn.

EXAMPLE 4 TABLE 4 Type of Percent crimp Percent Percent crimp nozzlesused elongation crimp recovery Conventional 43.5 18.5 74.1 Presentinvention 55.7 23.4 77.5

The above data clearly show the advantage of the ejection nozzle of thepresent invention over the conventional one and, in the case ofpolyacrylic fibers, the processing speed of the yarn can be elevated farmore through elevation of the heating temperature.

What is claimed is:

1. A yarn crimping apparatus for manufacturing a bulky yarn comprising,rotationally driven crimping means including a surface havingprotuberances thereon defining a multiplicity of fiber-receptive spacesfor crimping yarn fibers delivered into said spaces, an ejection nozzlespaced from said surface for ejecting plastified yarn fibers therefromand delivering the yarn fibers in a plastified state into said spaces assaid crimping means is driven for crimping said yarn, means fortaking-off the crimped yarn from said crimping means after setting thecrimped yarn and for taking it off at speeds automatically adjustedaccording to variations in the thermal shrinkability of the yarn fibers,and means to supply the yarn to said nozzle at a substantially constantsupply speed.

2. A yarn crimping apparatus according to claim 1, including coactingmeans to set the yarn disposed intermediate said nozzle and said meansfor taking-off the crimped yarn.

3. A yarn crimping apparatus according to claim 1, in which said meansfor taking off said yarn comprises two rotationally driven conicalrollers coacting to take-off said yarn.

4. A yarn crimping apparatus according to claim I, in which saidprotuberances extend outwardly from said surface substantiallyperpendicularly thereto.

5. A yarn crimping apparatus according to claim 1, in which the distancebetween an outlet of said nozzle and said surface is no greater than 10mm.

6. A yarn crimping apparatus according to claim 1, in which the distancebetween an outlet of said nozzle and said surface is less than 10 mm.

7. A yarn crimping apparatus according to claim 1, in which saidprotuberances are substantially perpendicular to said surface, and inwhich said means for taking-off said crimped yam comprises meansdisposed to take 011' the yarn from said crimping means substantiallyperpendicularly to said surface.

8. A yarn crimping apparatus according to claim 1, in which said meansfor taking-off said crimped yarn comprises coacting driven conicalrollers having their greatest diameter disposed in a direction towardwhich said crimping means rotates.

1. A yarn crimping apparatus for manufacturing a bulky yarn comprising,rotationally driven crimping means including a surface havingprotuberances thereon defining a multiplicity of fiber-receptive spacesfor crimping yarn fibers delivered into said spaces, an ejection nozzlespaced from said surface for ejecting plastified yarn fibers therefromand delivering the yarn fibers in a plastified state into said spaces assaid crimping means is driven for crimping said yarn, means fortaking-off the crimped yarn from said crimping means after setting thecrimped yarn and for taking it off at speeds automatically adjustedaccording to variations in the thermal shrinkability of the yarn fibers,and means to supply the yarn to said nozzle at a substantially constantsupply speed.
 2. A yarn crimping apparatus according to claim 1,including coacting means to set the yarn disposed intermediate saidnozzle and said means for taking-off the crimped yarn.
 3. A yarncrimping apparatus according to claim 1, in which said means for takingoff said yarn comprises two rotationally driven conical rollers coactingto take-off said yarn.
 4. A yarn crimping apparatus according to claim1, in which said protuberances extend outwardly from said surfacesubstantially perpendicularly thereto.
 5. A yarn crimping apparatusaccording to claim 1, in which the distance between an outlet of saidnozzle and said surface is no greater than 10 mm.
 6. A yarn crimpingapparatus according to claim 1, in which the distance between an outletof said nozzle and said surface is less than 10 mm.
 7. A yarn crimpingapparatus according to claim 1, in which said protuberances aresubstantially perpendicular to said surface, and in which said means fortaking-off said crimped yarn comprises means disposed to take off theyarn from said crimping means substantially perpendicularly to saidsurface.
 8. A yarn crimping apparatus according to claim 1, in whichsaid means for taking-off said crimped yarn comprises coacting drivenconical rollers having their greatest diameter disposed in a directiontoward which said crimping means rotates.